Firefighters in Philadelphia were battling a four-alarm fire that engulfed a massive warehouse on Monday morning.

The fire broke out at the J.S. Fesmire Hauling facility in the 5100 block of Darkrun Lane in the city’s Wissinoming neighborhood, FOX29 Philadelphia reported.

About 140 firefighters responded to fight the flames, according to the Philadelphia Fire Department.

The fire was placed under control at 11:21 a.m., the department said.

PHILADELPHIA BUSINESS OWNER, ACCOMPLICE CHARGED FOR STARTING BLAZE THAT KILLED FIREFIGHTER

4-alarm fire in Philadelphia

Dark smoke fills sky as crews respond to four-alarm fire in Philadelphia. (WTXF)

Fire officials warned nearby residents who are sensitive to smoke to stay indoors.

The Philadelphia Health Department urged residents to avoid the area or to stay inside as inspectors collect air samples and assess air quality for any potential threat.

"At this time, no specific hazardous substances have been identified, and we are taking this action out of an abundance of caution," the department said.

FOX29 captured aerial photos and video of dark smoke billowing from the structure's roof.

Philly warehouse fire

Fire officials warned nearby residents who are sensitive to smoke to stay indoors. (WTXF)

The incident began around 9:40 a.m. when there was a report of a person trapped under a forklift and a possible explosion, WPVI-TV reported.

THIEVES RANSACK SAN FRANCISCO BUILDING TWICE AFTER IT CATCHES FIRE: REPORT

The trapped individual was extricated and taken to a hospital, the report said.

Black smoke over warehouse

The incident began around 9:40 a.m. when there was a report of a person trapped under a forklift and a possible explosion, WPVI-TV reported. (WTXF)

CLICK TO GET THE FOX NEWS APP

No update on the person’s condition or details about the reported explosion was immediately available.